Dynamically generated dental articulator controls

ABSTRACT

This invention relates to improved methods and apparatus for recording and simulating the condylar movement of an individual. This invention also provides a dental articulator which is designed to simulate the jaw or condylar movements of a patient. This instrument enables a dentist to obtain the necessary diagnostic information for treatment of the occlusal irregularities, such as malocclusion, and the fabrication of dental cast or “dentures”.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/641,235 filed Oct. 15, 2012; which is a 371 of InternationalApplication PCT/US2011/032674 filed Apr. 15, 2011; which claims benefitof provisional application No. 61/325,200, all of which are incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates to an improved method to make dentalrestorations and dentures, the tools used to make these restorations anddentures and to dental articulators and, more particularly, to animproved articulator which allows for accurate simulation of the jaw orcondylar movements of a patient and accurate interchangeability ofdental casts.

BACKGROUND OF THE INVENTION

Currently dentists utilize a set of impression trays to make a mold ofthe patient's teeth. This mold is filled will plaster to create a modelof the patients teeth. The plaster model of the patient's teeth is thenused by the dentist as a substructure to build either dental crowns orbridges. This model of the upper and lower dental arch is then placed ina dental articulator to allow the dentist or dental technician to make acrown or bridge. A bite transfer or some similar tool is used to alignthe models in the articulator. Once the upper and lower dental archmodels are aligned the bite transfer is discarded. The dental technicianthen creates the dental restoration, crown or bridge. Once completed,the restoration is returned to the dentist for “try-in” and fitting.This fitting requires the dentist to match the restoration to thepatients jaw movements.

For dentures, dentists currently utilize a set of impression trays tocapture a mold of the patient's boney structure or ridge preparation forany dentures the dentist or dental technician make. This mold is filledwith plaster, which is used to create a model that is then placed in adental articulator. The dentist or dental technician will then make aneducated guess as to the correct spacing between the models and as tothe patients lip line. A set of “try-in” rims are created to test theassumptions made by the dentist and dental technician. The placement ofthe models in the articulator is then adjusted based on themodifications to the “try-in” rims. A set of “try-in” dentures is madeout of wax and “tried-in” the patient's mouth. If any adjustments aremade to this set of dentures, a second try-in is performed. Once theseadjustments are complete, the final denture set is made from the try-inset and returned to the Dentist for final try-in and fitting.

The purpose of a dental articulator is to simulate the jaw or condylarmovements of a patient. This instrument enables a dentist to obtain thenecessary diagnostic information for the treatment of occlusalirregularities, such as malocclusion, and the fabrication of dentalcasts or “dentures.”

U.S. Pat. No. 4,034,474 (“the Lee Patent”) and U.S. Pat. No. 4,034,475,disclose a simplified system for measuring jaw movements, andinformation useful in setting and operating dental articulators. It isfurther suggested in those patents that plastic guide blocks of the typedisclosed in the earlier Lee Patent be classified according to certaincharacteristics of jaw movements to provide a series of average valueblocks from which the pair most closely fitting the measurements of aparticular patient's condylar movements may be selected. Such guideblocks have curved walls which produce movement that closely simulates apatient's particular condylar movements, thus enabling a dentist totreat accurately an occlusal or denture problem without requiring thepresence of the patient.

While these methods have been available for some time, the methods havenot accurately and precisely recorded the patent's particular condylarmovements. The methods currently in place fail to record the effects ofboth the incisal guidance and posterior guidance, in a single record,which are necessary to create a reliable non-linear duplication of thecondylar guidance.

Thus there is a need for an economical and simple method to accuratelyreplicate the unique path of motion when performing dental restorations.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to an improved method to make dentalrestorations and dentures. More particularly, the present invention isdirected to an improved dental articulator that allows for accuratesimulation of the jaw or condylar movements of a patient and accurateinterchangeability of dental casts and the use of that improved dentalarticulator to make dental restorations and dentures.

This process is unique in at least two aspects relating to common dentalpractice. First, there is an expectation of recording balancing(non-working side) guides for registering the medial wall of the glenoidfossa. Second, all guidance is patient initiated and guided with verbalcoaching from clinician encouraging maximal muscular effort.

In the present invention, an improved dental articulator is described.The dental articulator includes: an upper frame and a lower frame forsimulating the lower dental arch and the upper dental arch; one of theframes having a pair of condyle mounted thereon; a pair of removablecondylar tables mounted on the other of the frames; a malleable materialdeposited in the condylar tables; an incisal pin mounted to one of theframes; a removable anterior guide table; and a malleable materialdeposited in the anterior guide table

In accordance with another aspect of this invention, a method ofrecording three-dimensional jaw movements and transferring the record toan improved dental articulator is provided. This method, which can beused to make dental restorations, includes the steps of: producing astandard impression of a patient's dentition; recording the functionaldynamics of occlusion using impression material by having the patientperform an immediate lateral move, requesting the patient to bite backwith strenuous force in right and left directions to produce afunctionally generated path (“FGP”) record; taking measurements using abite plate; producing a standard model of the patient's upper dentalarch and lower dental arch; placing the model of the upper arch andlower arch in the improved articulator utilizing the condylar andanterior guide setup boxes; placing the FGP record in the articulator;placing condylar and anterior guide tables in the improved articulator,the condylar and anterior guide table filled with a malleable material;manipulating the model of the upper dental arch and the lower dentalarch to scribe a path into the malleable material; and removing the FGPrecord and allowing malleable material to harden.

In accordance with another aspect of this invention, a method ofrecording three-dimensional jaw movements in an edentulous patient andtransferring the record to the improved dental articulator is provided.This method can be used to make dentures and includes the steps of:producing a standard impression of a patient's upper and lower jaw boneforms; placing a Vertical Dimension of Occlusion (“VDO”) tool in thepatient's mouth to measure the intraoral spacing between the upper andlower jaw and the lip line; attaching a spacing rim to the VDO withimpression material placed on the top and bottom rear surface to thespacing rim, and placing the VDO and spacing rim in the patients mouthto record the rear spacing of the patients upper and lower jaw; placingthe model of the upper arch and lower arch in the improved dentalarticulator utilizing the VDO and spacing rim to set the correctintraoral spacing of the upper and lower models, utilizing the condylarand anterior guide setup boxes; creating a set of Eric's rims in theimproved articulator utilizing the individual patients articulationsetup; Eric's rims are placed into the patients mouth to recorded thefunctional dynamics of occlusion by having the patient perform severallylateral moves, requesting the patient to bite back with strenuous forcein right and left directions to produce a FGP record; removing theEric's rims from the patient's mouth and using the marks indicated onthe Eric's rims material is removed; returning the Eric's rims to thepatient's mouth and repeating the process until the Eric's rims arefully balanced; placing the Eric's rims back into the improvedarticulator; placing condylar and anterior guide tables in the improvedarticulator, the condylar and anterior guide table filled with amalleable material; manipulating the model and Erie's rims of the upperdental arch and the lower dental arch to scribe a path into themalleable material; removing Eric's rims record and allowing malleablematerial to harden; and making a temporary denture of wax utilizing animproved functionally balanced Posterior Guided Occlusion teeth, thatmatches curve of Eric's rims and the benefits of the improved dentalarticulator.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter which form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand specific embodiment disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present invention. It should also be realized by thoseskilled in the art that such equivalent constructions do not depart fromthe spirit and scope of the invention as set forth in the appendedclaims. The novel features which are believed to be characteristic ofthe invention, both as to its organization and method of operation,together with further objects and advantages will be better understoodfrom the following description when considered in connection with theaccompanying Figures. It is to be expressly understood, however, thateach of the Figures is provided for the purpose of illustration anddescription only and is not intended as a definition of the limits ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference isnow made to the following descriptions taken in conjunction with theaccompanying Figures and drawings, in which:

FIG. 1 shows improved dental articulator with model.

FIG. 2 shows an exploded view of the improved dental articulator.

FIG. 3 shows a side view Vertical Dimension of Occlusion with Lip LineTab.

FIG. 4 shows a side view of the Eric's Rim.

FIG. 5 shows the condylar table set-up box

FIG. 6 shows the condylar table box.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, “a” or “an” means one or more than one.

The methods and apparatus of the present invention will now beillustrated with reference to FIGS. 1 through 4. It should beunderstood, that these are merely illustrative and not exhaustiveexamples of the scope of the present invention and that variations whichare understood by those having ordinary skill in the art are within thescope of the present invention.

Referring to FIGS. 1 and 2, an example of an improved dental articulatoris shown. The dental articulator is used to hold models of the upperdental arch 127 and the lower dental arch 137 and simulate the movementof the jaw when fabricating dental restorations such as crowns, bridges,and dentures.

The dental articulator has an upper frame 120, and lower frame 130 usedto mount the model of the upper dental arch 127 and the model of thelower dental arch 137. The model of the upper dental arch 127 is held tothe arm 121 of upper frame 120 by a conventional mounting plate 122 andthe model of the lower dental arch 137 is held to the arm 131 of lowerframe 130 by a conventional mounting plate 132. Both models are attachedto the mounting plates using plaster or other material. In the preferredembodiment, both mounting plates 132 and 142 are held to the articulatorby a snapping feature or magnetic feature designed into the mountingplate; however, other securing mechanisms, such as screws and the like,are envisioned. The position of the upper dental arch 127 is adjusted byadding material to area 124 between the upper dental arch 127 andmounting plate 122. Similarly, the position of the lower dental arch 137is adjusted by adding material to area 134 between the lower dental arch137 and mounting plate 132.

The dental articulator has a pair of posts 150 with condyles 151.Condyle 151 fit with condylar table 160 to simulate the temporalmandible joint of the patient. The condyle can be any shape the can beused to accurately represent the motion of the of the patients jaw.However, in the preferred embodiment, a spherical shaped condyle isused.

The condylar table 160 of the present invention consists of a removablebox that is connected to the dental articulator. As shown in FIG. 6,condylar table 160 includes an open box 161. The open box 161 allows amalleable material to be placed inside the box as well as to allowcondyle 151 to enter the condylar table 161. The malleable material canbe any self curing material such as methyl methacrylate, two part epoxy,urethane, sodium alginate, agar, condensation-cured silicones, andaddition-cured silicones such as polyvinyl siloxane, wax or similarmaterial. The setup condylar table is similar to the removable condylartable, however the box is not open, but instead includes an indentationto receive the condyle 151. The setup anterior guide table is similar tothe removable anterior guide table; however the box is not open, butinstead includes an indentation to receive the Incisal Pin 170. Thesetup condylar tables and the anterior guide table are removed and savedfor future use.

Dental articulator also has an incisal pin 170 and incisal table 171.Incisal pin 170 is utilized to set the normal distance between the upperdental arch 127 and the lower dental arch 137. The incisal table 171consists of a removable box that is connected to the dental articulator.Like the condylar table 161, the front of the box is open to allow thesame malleable material as used in the condylar table 161 to be placedinside the box. This allows the incisal pin 170 to enter the incisaltable 171.

Additionally, a removable set-up condylar tables and set-up incisaltables are used with the improved dental articulator. FIG. 5 shows atypical set-up table 600. The incisal pin 170 is held in place in thearm 121 by a set screw 173. The set-up table typically is a closed boxor block that prevents the condyle 151 or incisal pin 170 fromcompletely entering the box. The setup tables may also include anindentation 601 that allows the condyle 151 or incisal pin 170 to rest.This allows the dentist or dental technician to set the upper and lowerarch in stable in a stable occlusal position before condylar table 160and incisal table 170 are placed in the improved articulator.

The improved dental articulator can be used to make dental restorationsand dentures. The procedure for using the improved dental articulator isdescribed in further detail below.

Generally, the improved dental articulator can be used to make dentalrestorations, such as crowns and bridges, using the following steps:preparing the teeth for restoration; making an impression of the teeth;recording the jaw movements of a patient to produce a functionalgenerated path (“FGP”) record; producing the upper and lower model ofthe teeth; transferring the FGP record to the improved dentalarticulator to produce a model of the jaw movements; and reproducing thejaw movements in the articulator to create a custom condylar table. Eachof these steps will be discussed in detail below.

While the following describes the method of the present invention forthe restoration of a tooth, specifically the preparation of a crown,those skilled in the art will understand that this method can be appliedto any dental restoration procedure and is particularly useful inrestorations involving multiple teeth or restorations where a terminaltooth is missing.

Typically the first step in applying the present invention requires thepreparing the tooth for the restoration. Generally the preparation of atooth for a crown involves the irreversible removal of a significantamount of tooth structure. When preparing a tooth for a crown,typically, the enamel is totally removed and the finished preparationis, thus, entirely dentin. The amount of tooth structure required to beremoved will depend on the material(s) being used to restore the tooth.For example, if porcelain is applied to a gold crown, the total tooth isreduced minimally 1.5 mm.

After the tooth is prepared, a standard impression of the dentition ismade, allowing accurate models of the teeth to be made later. Animpression is carried out by placing a liquid material into the mouth ina customized tray. The material then sets to become an elastic solid,and when removed from the mouth retains the shape of the teeth. Commonmaterials used for dental impressions include, but are not limited to,sodium alginate, agar, condensation-cured silicones, and addition-curedsilicones such as polyvinyl siloxane.

When crowns or bridges are made using this technique, the complexrelationship that defines the functional dynamics of occlusion isrecorded using a thermoplastic transfer material in a bite plate. Thebite plate has a tongue and record area. The thermoplastic transfermaterial located in record area (re-enforced wax, compound material, orThermacryl) is warmed to a plastic state, adapted to the prepared teeth,and the FGP registration is recorded.

Unlike the standard “chew-in” procedure, the method of this inventionuses a modified procedure with more aggressive mastication used togenerate the FGP record. Specifically, the patient or subject is coachedinto an immediate lateral move and then asked to bite back withstrenuous force in right and left directions. Care is taken to ensurethat the subject uses significant maximal effort when clenching theteeth together from the lateral position.

The impressions are then used to generate the models of the patient'steeth. The models of the upper and lower dental arches are mounted in animproved articulator as described above. This allows for of transferringmeasurements relating to the location and angle of the teeth to thearticulator. Once the models of the upper and lower dental arches aremounted in the improved dental articulator, the FGP record is thenplaced in the articulator. The removable condylar table and theremovable guide table, which are filled with a malleable material, suchas a thermoplastic or other material as described above, are placed inthe improved articulator. The upper and lower dental arches are thenmanipulated by working the upper and lower frames of the dentalarticulator to scribe the functional path into the malleable materialstored in the condylar and anterior guide tables. Once this is complete,the FGP record is removed and the malleable material is allowed toharden.

Typically, the improved dental articulator can also be used to makedentures. The steps to make dentures using the improved dentalarticulator is similar to the steps used to make dental restorations,however, there are some notable differences, which are discussed furtherbelow.

While the following describes the method of the present invention forthe manufacture of dentures, those skilled in the art will understandthat this method can be applied to any dental restoration procedure andis particularly useful in restorations involving manufacture of full orpartial dentures.

The first step in applying the present invention to make denturesrequires preparing the gums for the restoration. Generally thepreparation of the edentulous gums requires the creation of a specialimpression tray.

After the impression tray is prepared, a standard impression of theedentulous ridge is made. An impression is carried out by placing aliquid material into the mouth in the customized tray. The material thensets to become an elastic solid, and when removed from the mouth retainsthe shape of the gum and ridge. Common materials used for dentalimpressions include, but are not limited to, sodium alginate, agar,condensation-cured silicones, and addition-cured silicones such aspolyvinyl siloxane.

To aid in placing the models of the patients edentulous ridge in theimproved dental articulator, the intraoral spacing of the patient'smouth is measured by placing a Vertical Dimension of Occlusion (“VDO”)tool in the patient's mouth to measure the intraoral spacing between theupper and lower jaw and the lip line. The VDO tool 400, which is shownin FIG. 3, has an upper rest 401, a lower rest 403, a lip line spacingtab 405 and a spacing rim 410. The upper rest 401 has a cylindricalportion 402 that slides within the cylindrical portion 404 lower rest403 and allows the dentist to set the intraoral spacing between theupper ridge and the jaw. Once the correct intraoral spacing is adjusted,the lip line spacing tab 403 is used to mark the patients lip line andlock the adjustments in place. This is done by snapping the lip linespacing tab 403 into a notch in the cylindrical portion 404 of lower liprest 403, which holds the cylindrical portion 402 of upper rest 401 inplace. Once the intraoral spacing has been set, the spacing rim 410 isattached to the VDO tool 400 and impression material placed on the topand bottom rear surface to the spacing rim. The VDO tool 400 withspacing rim 410 are placed in the patients mouth to record the rearspacing of the patients upper and lower jaw. These measurements from VDOtool 400 are then use to place the model of the upper arch and lowerarch in the improved dental articulator. Utilizing the VDO tool andspacing rim allows the correct intraoral spacing of the upper and lowermodels to be transferred to the model. This is typically done using thecondylar and anterior guide setup boxes.

The impressions are then used to generate the models of the patient'steeth. The models of the upper and lower dental arches are mounted inthe improved articulator as described above. VDO Tool 400, when used toplace the dental models during the set-up of the improved articulator,allows measurements relating to the location and angle of the teeth tobe transferred to the articulator.

Once the upper and lower models are set in the improved dentalarticulator, Eric's Rim bite blocks can be created in the improvedarticulator utilizing the individual patient's articulation setup.Eric's Rim Bite blocks, are created using a soft wax to space the Eric'srims. FIG. 4 shows a typical Eric's rim curve 500. Once created, theEric's rims are returned to the dentist to be chewed-in by the patient.

When dentures are made using this technique, the complex relationshipthat defines the functional dynamics of occlusion is recorded using athermoplastic transfer material and a unique transfer rim or Eric's Rim.The rim has a tongue and record area. The thermoplastic transfermaterial located in record area. This recorded area can be made from theFGP registration that is recorded in a “chew-in” procedure.

Unlike the standard “chew-in” procedure, the method of this inventionuses a modified procedure with more aggressive mastication used togenerate the FGP record. Specifically, the patient or subject is coachedinto an immediate lateral move and then asked to bite back withstrenuous force in right and left directions. The Eric's rims are placedin the patient's mouth. Care is taken to ensure that the subject usessignificant maximal effort when clenching the Rims together from thelateral position. Areas of contact are recorded using bite registrationtape or similar material. The Rims are removed from the patient's mouthand the areas of contact are removed from the surface of the Eric's Rimusing a Dental Hand Piece and a suitable burr to remove a thin layer ofmaterial where the rim's contact. This procedure is repeated until theEric's rims are in balance. This balanced position is where there is asimilar registration of contact across the rim, with no noticeable lowareas or areas unmarked by the registration tape.

Once the Eric's rims are balanced, they are returned to the improveddental articulator and condylar and anterior guide tables are filledwith a malleable material and placed in the improved articulator. Asdiscussed above the malleable material can be any malleable material,the upper and lower Rims are then manipulated by working the upper andlower frames of the dental articulator to scribe the functional pathinto the malleable material stored in the condylar and anterior guidetables. Once the malleable material hardens the model can then be usedto make a temporary denture of wax utilizing improved functionallybalanced Posterior Guided Occlusion teeth that match the curve of theEric's rims.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by the appended claims. Moreover, thescope of the present application is not intended to be limited to theparticular embodiments of the process, machine, manufacture, compositionof matter, means, methods and steps described in the specification. Asone of ordinary skill in the art will readily appreciate from thedisclosure of the present invention, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the present invention.Accordingly, the appended claims are intended to include within theirscope such processes, machines, manufacture, compositions of matter,means, methods, or steps.

What is claimed is:
 1. A method for making dental restorations using adental articulator comprising an upper frame for simulating the upperdental arch and a lower frame for simulating the lower dental arch, apair of condyles on the lower frame, one or more removable condylartables received in the upper frame, an incisal pin on the upper frame,and a removable anterior guide table received in the lower frame, thepair of condyles configured to be moveable in the one or more removablecondylar tables to allow movement of the upper frame and the lower framewith respect to each other, the incisal pin configured to interact withthe removable anterior guide table, the method comprising: producing animpression of a patient's dentition; recording functional dynamics ofocclusion to create a functionally generated path record; producing amodel of the patient's upper dental arch and lower dental arch; placingthe model of the upper arch and the lower arch in the dentalarticulator; placing the functionally generated path record in thedental articulator; filling the removable condylar tables and removableanterior guide table with a malleable material; and manipulating themodel of the upper dental arch and the lower dental arch to scribe apath into the malleable material.
 2. The method of claim 1 furthercomprising removing the functionally generated path record and allowingthe malleable material to harden.
 3. The method of claim 1, wherein thefunctionally generated path is recorded by placing impression materialinto the patient's mouth and having the patient bite with strenuousforce in the left and right directions.
 4. A method for making denturesusing a dental articulator comprising an upper frame for simulating theupper dental arch and a lower frame for simulating the lower dentalarch, a pair of condyles on the lower frame, one or more removablecondylar tables received in the upper frame, an incisal pin on the upperframe, and a removable anterior guide table received in the lower frame,the pair of condyles configured to be moveable in the one or moreremovable condylar tables to allow movement of the upper frame and thelower frame with respect to each other, the incisal pin configured tointeract with the removable anterior guide table, the method comprising:producing an impression of a patient's upper arch and lower arch;measuring the intraoral spacing between the upper and lower jaw and thelip line; placing the model of the upper arch and the lower arch in thedental articulator using the previously measured intraoral spacing;creating a curved transfer rim comprising a tongue and record area, therecord area comprising a transfer material; recording, on the recordarea of the curved transfer rim, functional dynamics of occlusion of thepatient to create a functionally generated path record; balancing thecurved transfer rim to the patient; placing the curved transfer rim inthe dental articulator; filling the removable condylar tables andremovable anterior guide table with a malleable material; andmanipulating the curved transfer rim within the articulator to scribe apath into the malleable material.
 5. The method of claim 4, furthercomprising using a condylar set-up box to set the upper arch and lowerarch in a stable occlusal set-up.
 6. The method of claim 4, wherein theinteroral spacing between the upper and lower jaw and the lip line ismeasured using a vertical dimension of occlusion tool.
 7. The method ofclaim 4, further comprising the step of removing the curved transfer rimfrom the dental articulator and allowing the malleable material toharden.
 8. The method of claim 4, wherein balancing the curved transferrim comprises removing transfer material deposited on the curvedtransfer rim until there is a similar registration of contact across thecurved transfer rim based on the unique dental or jaw function of thepatient, with no noticeable low areas or areas unmarked by registrationtape.
 9. The method of claim 4, wherein the transfer material is athermoplastic transfer material.